Goodwill and Other Intangible Assets - Goodwill Assets (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($)
Goodwill Roll Forward
Goodwill, Beginning Balance	$ 631,212
Goodwill Additions	5,270
Goodwill, Translation Adjustments	(3,033)
Goodwill, Ending Balance	633,449
Operating Segments [Member] | Global Specialty Businesses [Member]
Goodwill Roll Forward
Goodwill, Beginning Balance	119,718
Goodwill Additions	128
Goodwill, Translation Adjustments	(2,141)
Goodwill, Ending Balance	117,705
Operating Segments [Member] | Americas [Member]
Goodwill Roll Forward
Goodwill, Beginning Balance	213,242
Goodwill Additions	1,208
Goodwill, Translation Adjustments	614
Goodwill, Ending Balance	215,064
Operating Segments [Member] | EMEA [Member]
Goodwill Roll Forward
Goodwill, Beginning Balance	140,162
Goodwill Additions	2,626
Goodwill, Translation Adjustments	(2,633)
Goodwill, Ending Balance	140,155
Operating Segments [Member] | Asia Pacific [Member]
Goodwill Roll Forward
Goodwill, Beginning Balance	158,090
Goodwill Additions	1,308
Goodwill, Translation Adjustments	1,127
Goodwill, Ending Balance	$ 160,525